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Topic: 16mm two track mag with matrix and Dolby A

Stephen Furley
Film God

Posts: 3059
From: Coulsdon, Croydon, England
Registered: May 2002

posted 10-11-2002 07:46 AM

I need to run some 16mm prints with sep-mag tracks. Most are mono or two track stereo, but one is four channel matrixed with Dolby A, like 35mm optical.

Have available a MPU-1 unit with two spare channels, and a CP65, but I don't think the '65 can put the mag/aux input through the decoder, is this correct? I know that the non sync input can go through the decoder, but I don't know if there is any way to put it through the Cat. 222. Any ideas, apart from hireing in extra gear, just for one film.

Thanks.

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Frank Angel
Film God

Posts: 5305
From: Brooklyn NY USA
Registered: Dec 1999

posted 10-11-2002 07:53 AM

Use any comsumer ProLogic decoder unit to derive the matrixed 4 channels.

Take the 2 channel output from the MPU-1 mag preamp into the consumer unit and then its four channel out back into the processor. It will be easy and consumer cheap.

Frank

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Stephen Furley
Film God

Posts: 3059
From: Coulsdon, Croydon, England
Registered: May 2002

posted 10-11-2002 08:30 AM

quote:
Use any comsumer ProLogic decoder unit to derive the matrixed 4 channels.
Take the 2 channel output from the MPU-1 mag preamp into the consumer unit and then its four channel out back into the processor. It will be easy and consumer cheap.

But what about the Dolby A? A conuumer ProLogic unit wouldn't handle that. I need to get the signals through the noise reduction, after the pre-amps, and before the matrix decoder. This is a private show for the film maker to show off his work to possible future clients, so it's got to be done right. The MPU-1/CP65 combination has all the necessary modules to do the job, but I can't see how to set it up to do this. The only other way I can see would be to hire in a couple of old 364s to do the noise reduction, but I'm trying to avoid that.

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Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99

posted 10-11-2002 11:29 AM

unplug the optical preamp card and then connect the MPU to the terminals onthe back of the CP65 marked Preamp output
Then select 04 for the A type matrix print

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Frank Angel
Film God

Posts: 5305
From: Brooklyn NY USA
Registered: Dec 1999

posted 10-11-2002 01:06 PM

This is why Gordon is the Film God.

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Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99

posted 10-11-2002 09:38 PM

No that is how Print masters can be handled very effortessly

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Steve Kraus
Film God

Posts: 4094
From: Chicago, IL, USA
Registered: May 2000

posted 10-12-2002 07:35 PM

I used to have a CP-50 whose preamp card I modified so I could feed external inputs before the changeover switching FET's so I had two pairs of inputs for feeding dubbers or other sources or I could switch it to normal optical. I also added a switch to the meter/filter card to kill the Academy filter even if NR was off.

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Frank Angel
Film God

Posts: 5305
From: Brooklyn NY USA
Registered: Dec 1999

posted 10-15-2002 04:13 AM

So Steve, switching out the Academy filter can be easily done? I never really looked into how easy or difficult this would be myself, but now you have my interest; does the Dolby schmatic for the meter card have the filter circuit marked as such? I an not sure I am circuitry literate enough to be able to read a schematic and identify the filter circuit. If it isn't so marked, perhaps I can ask you to be good enough to describe what points have to be jumped or opened to switch the thing in and out. Thanks

Frank

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